Distribution network line fault section positioning method based on full-waveform information

Abstract

The invention discloses a distribution network line fault section positioning method based on full-waveform information. For the grounding fault, line selection is carried out through extreme value points of a cross-correlation function of the bus zero-sequence voltage and all outgoing line zero-sequence currents, and positioning is carried out according to the adjacent detection point zero-sequence current waveform standard drift rate of the whole action process of a fault occurrence and compensation device; for the interphase fault, line selection is carried out according to the overcurrent information obtained before action of a relay protection device, and positioning is carried out according to the adjacent detection point fault phase current waveform standard drift rate. The waveform data of the whole action process of a fault and arc extinction device are utilized, the current ubiquitous problems that when a small current grounding system encounters the single-phase grounding phase, the fault current is weak, the reliability is poor, and the sensitivity is low can be well solved, and meanwhile the system cannot get interference.

Description

technical field [0001] The invention relates to a method for diagnosing a distribution network line fault, in particular to a method for locating a distribution network line fault section based on full waveform information. Background technique [0002] According to statistics, during the operation of the power system, power outages caused by distribution network faults account for more than 95% of the total power outages, of which 70% are caused by single-phase ground faults or busbar faults. The neutral point of domestic and foreign distribution networks widely adopts non-effective grounding (small current grounding) to avoid power supply interruption when a single-phase grounding fault occurs. For single-phase-to-ground faults in distribution networks, due to weak fault characteristics, there has been a lack of reliable fault line selection and location methods. With the improvement of people's requirements for distribution network automation level, it is more urgent to ...

AI Technical Summary

Problems solved by technology

Injection signal methods include "S" injection method, AC-DC integrated injection method and parallel neutral resistance method. These methods increase the interference to the system and cannot detect instantaneous and intermittent ground faults.

Section location based on fault characteristic quantity includes zero-mode current comparison method, section zero-sequence admittance method, zero-sequence reactive power direction method, location based on phase current mutation, residual incremental method, traveling wave method, etc. This type of method has key problems such as difficulty in obtaining feature quantities and precise signal synchronization, and some methods have extremely low reliability when high-impedance grounding

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